While I do not have any specific experience at Arthur D Little, I have worked in a similar role as a consultant at McKinsey & Company. I am basing my answer off that experience.
The description of responsibilities and qualifications for this role are intentionally vague.
This is likely because the job responsibilities and qualifications for consultants change for each project the consultant works on. To understand this, you have to keep in mind that consultants work on specific projects (usually one at a time, but on occasion may work on a few at a time), each of which has a fixed duration and a fixed goal. The goal is usually to provide advice to clients (where clients are managers or management teams at companies paying the consultant). The type of advice required ranges greatly from one project to another, which means that the consultant must be very versatile to be successful on multiple studies. This is why the Arthur D. Little description is so vague.
So, what DO consultants do on a day-to-day basis?
As far as activities go, consultants at Arthur D. Little (as well as at any other consulting firm) are likely to encounter the following activities on a very regular (day-to-day) basis:
- Travel - It is very common for consultants to travel
- Conduct research - Finding the answers the client needs usually requires a lot of research to be gathered. This research is gathered together from a wide range of sources - good consultants will be industrious and creative with where they get their research results.
- Interview experts, clients, and customers - Interviews are often a good source for getting to the root of problems. At times, consultants will be interviewing any of a wide range of people to get intelligence on problems and how to solve them. The consultant on the consulting team is often tasked with setting up and conducting those interviews, and then synthesizing the findings and sharing them with other team members and clients.
- Create excel models forecasting financial performance, market size, and many other things - Consultants must often perform calculations for which there are no existing models or formulas. The standard method for performing and sharing these calculations is to use Microsoft Excel. (Beware - the use of the term "models" is quite different in other industries, including academic communities). The Consultant is often the person who would create these excel models.
- Create presentations and reports - The standard method for communicating findings to clients in the consulting industry is with the use of formal presentations. These are often conducted with the use of PowerPoint presentation slides. The consultant is tasked with creating these presentations and presenting many of them to the client. Successful consultants must be effective at communicating through written communications and presenting verbally as well.
- Many others - There are many other things involved with being a consultant, but the above items are most common.
Note: you did not specifically ask for an explanation of the qualifications or responsibilities. You asked what consultants DO, so that's where I focused my answer. If you would like to ask about the qualifications or responsibilities, I would suggest you ask those as separate questions, because each of them is a useful question on its own. ---